// Encyclopedia

The amount of bandwidth allotted to each channel in a communications system that transmits multiple frequencies such as fiber optics. It is measured as the spacing between center frequencies (or wavelengths) of adjacent channels. See guard band.

Channel Spacing in Optical Fibers

The first 10 Gbps example with 50 GHz spacing has a slight signal overlap, but with 100 GHz, there is none. The first example provides more bandwidth, but the overlap could be enough to cause significant crosstalk. (Illustration courtesy of Jeff Hecht.)